1620-68-4Relevant academic research and scientific papers
Effect of SnO2/Al2O3 ratio of Si-based MFI on its acidity and hydrophobicity: Application in selective hydroxyalkylation of p-cresol
Garade,Malwadkar,Niphadkar,Jha,Joshi,Rode
, p. 29 - 34 (2014)
Silica based MFI type molecular sieves with various SnO2/Al 2O3 ratios were synthesized from gels having molar compositions SiO2:xSnO2:yAl2O 3:0.23(TPA)2O:35H2O where 0 ≤ x ≤ 0.02 and 0 ≤ y ≤ 0.01. Recyclable, Al-free Sn-MFI catalyst showed 31% conversion of formaldehyde with 100% selectivity to 2,2′-methylenebis(4- methylphenol) in hydroxyalkylation of p-cresol with formaldehyde on account of moderate acidity and higher hydrophobicity.
Structure-activity studies of dodecatungstophosphoric acid impregnated bentonite clay catalyst in hydroxyalkylation of p-cresol
Garade,Kshirsagar,Jha,Rode
, p. 942 - 945 (2010)
Bentonite clay impregnated with dodecatungstophosphoric acid (20% DTP/BNT) showed an excellent activity, selectivity and stability [95% product yield with 94% selectivity to 2, 2′-methylenebis (4-methylphenol), DAM] for the hydroxyalkylation of p-cresol with formaldehyde at 353 K and for a mole ratio of 5. Ammonia-TPD results showed that an increase in total concentration of acid sites from 4.9 of parent bentonite to 11.6 micromoles per surface area NH3 (μmolS-1 NH3) of 20% DTP/BNT was due to a strong interaction of protons of bulk DTP with surface hydroxyl groups of BNT as evidenced by 31P NMR studies.
Solvent-free synthesis of trisphenols as starting precursors for the synthesis of calix[4]arenes using sulfonated multi-walled carbon nanotubes
Fareghi-Alamdari, Reza,Golestanzadeh, Mohsen,Zekri, Negar
, p. 3400 - 3412 (2016/05/09)
The condensation of phenol derivatives (12 substrates) with 2,6-bis(hydroxymethyl)phenols (BMP) (6 examples) is reported using sulfonated multi-walled carbon nanotubes (SO3H@MWCNTs) under solvent-free conditions as starting precursors for the synthesis of macrocyclic molecules of calix[4]arenes. The new protocol provides a series of trisphenol derivatives (21 examples) in high yields (up to 94%) and relatively short reaction times (15-120 min). Also, direct synthesis of calix[4]arenes from different trisphenols by use of the catalyst was reported (5 examples). Furthermore, the synthesized calix[4]arene was obtained using a one-pot method from simple and easily available starting materials such as p-cresol for the synthesis of 5,11,17,23-tetramethylcalix[4]arene-25,26,27,28-tetraol. Also, in this process SO3H@MWCNTs can be reused for seven runs with almost consistent efficiency and can be recovered by easy filtration.
An efficient synthetic approach to substituted trisphenols (phloroglucide analogues) using tungstosilicic acid in water
Fareghi-Alamdari, Reza,Khalafi-Nezhad, Ali,Zekri, Negar
, p. 887 - 892 (2014/04/03)
Tungstosilicic acid was found to be an efficient catalyst for the synthesis of trisphenols using the reaction of 2,6-bis(hydroxymethyl)phenols with phenols in an aqueous medium. The catalytic reactivity of tungstosilicic acid in boiling water was examined with a series of substrates, demonstrating that this catalyst is reactive in the presence of a variety of functionalities. Georg Thieme Verlag Stuttgart. New York.
The reaction of hexaalkylphosphorous triamides with oligophenols
Weber, Dirk,Habicher, Wolf D.,Nifantev,Teleshev,Zhdanov,Belsky
, p. 143 - 165 (2007/10/03)
Hexaalkylphosphorous triamides form in good yields 6-dialkylamino-12H-dibenzo[d.g] [1,3,2]dioxaphosphocins 2a-i in the reaction with oligophenols 1a-i. Heating the sterical hindered compounds 2a-f up to 315°C leads to the corresponding bicyclic phosphites 3a-d while the non-hindered phosphocins 2g-i react in refluxing xylene to give phosphites 3e-g. The phosphocin 2i formed another phosphocin 2i* during heating to 90°C in THF by "wandering" of the phosphorus moiety. The bicyclic phosphites 3h and 3i were prepared starting from tetraphenol 1h and pentaphenol 1i by reaction with hexaethylphosphorous triamide in refluxing xylene. The diphosphorylated triphenol 4 and tetraphenol 5 are formed in the reaction of the corresponding phenols with 2 eq. of hexaalkylphosphorous triamide.
A New Approach to the Synthesis of Phenol-Containing Macroheterocycles
Bordunov, Andrei V.,Lukyanenko, Nikolai G.,Pastushok, Victor N.,Krakowiak, Krzysztof E.,Bradshaw, Jerald S.,et al.
, p. 4912 - 4918 (2007/10/02)
A one-step method for the synthesis of new phenol-containing cryptands and cryptohemispherands by treating N,N'-bis(methoxymethyl)diazacrowns with the appropriate bis- and trisphenols is reported.This method, based on a special Mannich reaction, gives cyclized products without the need for protecting groups and high dilution conditions.Unusually high yields of cryptohemisherands were realized using a relatively high concentration of the starting materials (50 mmol/L) and in the absence of metal cations as template agents in the reaction mixture.These excellent yields can be explained by intramolecular hydrogen bonding which prevents polycondensation.This new method also allowed preparation of new phenol-containing cylindrical tricyclic ligands by first forming bisphenol-substituted diaza-18-crown-6 at 80 deg C followed by its reaction with a second bis(methoxymethyl)-substituted diaza-18-crown-6 at 144 deg C.Crystal structures of two cryptohemispherands are reported herein.A shorter internal distance between N and O atoms in 27 as compared to 6 (R = NO2, n = m = 2) indicates intramolecular hydrogen bonding in phenol-containing macrocycle 27.
Metal-template ortho-regioselective mono- and bis-de-tert-butylation of poly-tert-butylated phenols
Sartori, Giovanni,Bigi, Franca,Maggi, Raimondo,Porta, Cecilia
, p. 7073 - 7076 (2007/10/02)
A metal-template ortho-regioselective mono- and bis-de-tert-butylation of poly-tert-butylated phenol-formaldehyde oligomers is reported.
